The prism shield should be oriented at precisely 45º to the table. If it’s even 10 degrees off, you’ll see a squashed image, an upside-down image, or nothing at all.

Proper lighting is super-important. The lighting on your subject and paper should be approximately the same.

Want more info? New to the NeoLucida? Here’s how to get started:

To use the NeoLucida, begin by clamping it to a table or drawing board. Place your subject in front, with your paper on the table below the NeoLucida’s prism. Then comes the magical moment:

That’s right, lovely NeoLucida users: LOOK STRAIGHT DOWN.

Huh? Well, we’ve carefully observed dozens of people experiencing a camera lucida for the first time. And this seems to be the one big hurdle for new users. Looking straight down is absolutely critical to using a camera lucida properly! To help you trace your subject in front of you, we wrote this haiku:

You should look straight down at your pencil and paper through the prism edge

Have a look at Pablo, below:

That’s right—he’s looking straight down, less than an inch away from the eyepiece. And because he is, he observes his subject right-side-up. If you don’t see your pencil and paper, you’re not looking straight down. If you see your subject upside-down, you’re not looking straight down.

It’s so important to LOOK STRAIGHT DOWN, we even said it twice in our instructions. Here’s a view of the instructions that come with the NeoLucida; please pay special attention to Steps 5 and 6, with the yellow highlights:

We hope this helps get you started smoothly. Just remember: look straight down.
Here are NeoLucida Instructions as found inside the box (click for larger image):